Shaped explosive charge apparatus



Feb. 18, 1964 J. DELACOUR 3,121,389

SHAPED EXPLOSIVE CHARGE APPARATUS Filed Dec. 24, 1957 INVENTOR JACQUES DELACOUR HIS ATTORNEYS United States Patent 3,121,389 SHAPED EXPLOSIVE CHARGE APPARATUS Jacques Delacour, Paris, France, assignor to Societe de Prospection Electrique Procedes Schlurnherger, Paris, France, acorporation of France Filed Dec. 24, 1957, Ser. No. 704,936 Claims priority, application France Dec. 26, 1956 2 Claims. (Cl. 102-20) The present invention relates to shaped explosive charge apparatus and, more particularly, to novel and improved types of shaped explosive charge apparatus for use, for example, in perforating the tubular lining or casing of the inner wall of a bore hole together, in some cases, with the concrete or cement filling the space behind the casing.

Well known types of shaped explosive charge devices include a substantially conical-shaped or hollowed-out portion in the front end of the main explosive charge, the front conical section or hollowed-out portion having a metal liner, which in many cases is made of copper. This liner upon firing the shaped explosive charge is generally transformed into a comparatively important core which follows the high speed jet formed upon the explosion of the charge at a comparatively lower speed and acts to engage at least portions of the perforation formed by the jet so as to obstruct it over a substantial length. This at least partial stopping or obstruction of the perforation is highly objectionable since it is normally desirable that the perforation should remain fully open. This is particularly true when it is desired to perforate a bore hole lining, for example, in order to open it for purposes of production from petroleum deposits, etc.

Further, in conventional forms of shaped explosive charge devices wherein the weight of explosive material is very limited by reasons of the conditions of operation, it is necessary for the outer casing of the charge to be composed of solid metal. When the charge explodes, this casing, if made of solidmetal, is either disintegrated so as to form multiple splinters of variable sizes or it becomes partly molten or even vaporized, according to the nature of the metal forming the casing. In both cases, the resultant products formed from the casing after the explosion of the charge are carried along by the jet of exploded material formed by the detonation of the shaped explosive charge through the perforation produced by the jet. These products have a tendency to close at least partly the perforation either through a wedging therein of splinters in their solid state or through condensation of the vaporized metal over a more or less considerable depth within the perforation. This, as in the case of the core formed from the liner, results in a substantial reduction in the efliciency of the perforation as far as operation of the bore hole is concerned, especially so in the case of the working of petroleum carrying strata or deposits.

It is the purpose of the present invention to eliminate at least one or more of these disadvantages. With regard to the liner, it has been found, that in accordance with the invention, the above disadvantage may be obviated by the provision of a liner for the shaped explosive charge device which is not made of solid metal but is composed of compressed pulverulent metal, preferably a heavy metal which is sintered after compression, if required. It has been found that, upon firing of the shaped explosive charge device, with such a liner, the part of the liner which is not transformed into a' gaseous jet is completely atomized to form a powder of a granulometric value equivalent to that of the original powder. This powder is of such size that it does not act to stop or obstruct the perforation produced by the jet formed by the explosion of the shaped explosive charge.

Similarly, in accordance with the invention, the casing enclosing the shaped explosive charge may be formed from compressed powdered metal which may be subsequently sintered, if required, instead of from a solid metal. It has been found that such a casing has a number of advantages. For example, the confinement of the shaped explosive charge within a casing of this type had lead to improved effects. Also, a casing made from such compressed pulverulent metal is completely atomized under the action of the explosion of the shaped charge, so as to form a powder of a granulometric value equivalent to that of the original metal powder. It has also been found that there is no risk of this powder clogging or obstructing the perforation which is obtained by means of the explosive jet formed by the explosion of the shaped explosive charge.

The granulometric value of the puverulent metal or powder which may be used in either or both of the above described embodiments of the invention may in practice be selected within a broad range. For example, when compressed iron powder is used, the granulornetric value may be equal to or 10%(K) (sieving fractions expressed in terms of the Tyler Standard Screen Series).

In my copending application for United States patent Serial No. 614,395, dated October 8, 1956, now abandoned, for Shaped Explosive Charge Devices, it has been proposed to produce liners of a material such as titanium, adapted to react in an exothermic manner when they have engaged petroleum-carrying geological strata which are to be opened for productive operation. Experience has shown that, in this case also, it may be of advantage to produce such liners, for example, by means of compressed pulverulent titanium so as to increase still further the efficiency of the explosive charge.

For a more definite understanding of the principles and advantages of the invention, reference may be had to the following detailed description taken in conjunction with the accompanying figures of the drawing, in which:

FIGURE 1 is a side elevation in longitudinal section of a casing perforating apparatus including a shaped explosive charge device, in accordance with one embodiment of the invention; and

FIG. 2 is a side elevation in longitudinal section of a casing perforating apparatus including a shaped explosive charge device, in accordance with a further embodiment of the invention.

In FIG. 1, a portion of an elongated, hollow, cylindrical perforator casing 11 is suspended in a conventional manner by a cable and hoisting mechanism (not shown) in a bore hole 12 having a metallic casing 13 forming the inner wall of the bore hole. A plurality of shaped explosive charge devices 14, only one of which is shown, may be supported in a conventional manner within the elongated cylindrical casing 11 in superposed, spacedapart relationship in such a manner that when fired either together or individually, each of the shaped explosive charge devices forms a jet adapted to perforate the well casing 13 and, if required, any cement or concrete cast between the well casing and the bore hole 12..

The shaped explosive charge device 14 comprises a covering means or casing 15 enclosing a shaped explosive charge 16 having a covering means or liner 17 of substantially conical form in the forward portion thereof forming a corresponding hollowed-out recess directed toward the front of the device in a conventional manner. A conventional igniting means 18 comprising a detonating cord, for example, passes through the rear portion of the casing 15 in such a manner as to enable the firing of the shaped explosive charge device 14 in a conventional manner.

On assembly, the shaped charge device 14 is intro- 3 duced sideways through a port 19 formed in the Wall of the perforator 11, and is held in position by a conventional plug 28 which is screwed into the port 19. While the front end of the casing 15 of the shaped charge device 14 bears against the cooperating edge of the port and plug at one end, its other end is fitted inside a recess formed in the opposite wall of the perforator casing 15. The plug 20 is adapted to be perforated in its central section by the jet produced by the explosion of the shaped charge device 14.

In accordance with the invention, the casing 15 of the shaped charge device 14, instead of being made of a solid metallic material, is made, for example, of pulverulent iron, the granulometric value of which is equal to about the pulverulent iron being compressed so as to show an apparent specific gravity equal to about 6.5. In order to give the casing 15 the necessary mechanical properties, the casing 15 is surrounded by an outer very thin casing or outer covering 21 of aluminum having a thickness of about .0118 in.

In the embodiment of FIG. 2, a shaped expiosive charge device 30 is positioned within the hollow, elongated, cylindrical perforator casing 11 in substantially the same manner as the shaped charge device 14, with its forward end adapted to bear against the cooperating edge of the port 19 and the plug 24), and with the rear end of a casing 31 for the shaped charge device fitted inside a recess formed in the opposite wall of the perforator casing 11. The charge is adapted to be fired by the igniting means 18 in a conventional manner.

In contrast with the embodiment of FIG. 1, the shaped charge casing 31 enclosing the shaped explosive charge 32 may be composed either of a solid metallic substance, such as steel, or may take the form of the casing 15 with the corresponding outer casing 21, as shown in FIG. 1. In accordance with the invention, a substantially conical covering means or liner 33 situated in a conventional manner in a hollowed-out depression in the forward end of the explosive charge 32 may be composed of a heavy compressed metal such as copper or iron, or, when it is desired to obtain the exothermic effect discussed in the aforementioned copending application, the liner may be composed of compressed pulverulent titanium.

Thus there has been provided, in accordance with the invention, novel and improved shaped explosive charge devices having either the charge casing, the charge liner, or both, composed of a suitable compressed pulverulent material, so as to eliminate at least some of the products of the explosion of the shaped explosive charge device tending to obstruct the perforation formed by the jet produced by the shaped explosive charge.

It will be evident to those skilled in the art that the above-disclosed embodiments are meant to be merely exemplary and that they are susceptible of modification and variation without departing from the spirit and scope of the invention. Therefore, the invention is not deemed to be limited except as defined by the appended claims.

'I claim:

1. A shaped explosive charge device for use in perforating apparatus and the like, comprising a shaped explosive charge having a hollowed-out depression at one end, a liner for said charge disposed in said depression, a casing having a substantial thickness which is considerably greater than that of the liner and sufiicient to effectively confine the charge when detonated, said casing completely surrounding the portion of the surface of said shaped explosive charge other than said one end, said casing being made of compressed and sintered metal powder and an outer cover of sheet material in close fitting contact with at least a substantial portion of said casing, said sheet material being very thin relative to the thickness of said casing.

2. A shaped explosive charge device for use in perforating apparatus and the like, comprising a shaped explosive charge having a hollowed-out portion at one end, a liner for said charge disposed in said portion, a casing made of compressed metal powder having a substantial thickness which is considerably greater than that of the liner and suificient to effectively confine the charge when detonated, said casing completely surroun ing the portion of the surface of said shaped explosive charge other than said one end, and an outer cover of metal sheet material in close fitting contact with at least a substantial portion of said casing, said metal sheet material being very thin relative to the thickness of said casing.

References Cited in the file of this patent UNITED STATES PATENTS 2,605,703 Lawson Aug. 5, 1952 2,629,325 Swcetman Feb. 24, 1952 2,742,857 Turechek Apr. 24, 1956 2,761,383 Sweetman Sept, 4, 1956 2,782,715 Udry Feb. 26, 1957 2,785,631 Blanchard Mar. 19, 1957 FOREIGN PATENTS 131,701 Australia Nov. 9, 1945 658,625 Great Britain Oct. 10, 1951 

1. A SHAPED EXPLOSIVE CHARGE DEVICE FOR USE IN PERFORATING APPARTUS AND THE LIKE, COMPRISING A SHAPED EXPLOSIVE CHARGE HAVING A HOLLOW-OUT DEPRESSION AT ONE END A LINER FOR SAID CHARGE DISPOSED IN SAID DEPRESSION, A CASING HAVING A SUBNSTANTIAL THICKNESS WHICH IS CONSIDERABLY GREATER THAN THAT OF THE LINER AND SUFFICIENT TO EFFECTIVELY CONFINE THE CHARGE WHEN DETONATED, SAID CASING COMPLETELY SURROUNDING THE PORTION OF THE SURFACE OF SAID CASING BEING MADE OF COMPRESSED AND SINTERED METAL POWDER AND AN OUTER COVER OF SHEET MATERIAL IN CLOSE FITTING CONTACT WITH AT LEAST A SUBSTANTIAL PORTION OF SAID CASING, SAID SHEET MATERIAL BEING VERY THIN RELATIVE TO THE THICKNES OF SAID CASING . 